Is Something Growing In AC? How To Spot Mold Before It Spreads

December 9, 2025

Living in our humid climate, keeping your cooling system clean is crucial for your health. Whether you are a homeowner relying on residential air conditioning Gold Coast units to beat the heat, or a business manager maintaining commercial air conditioning Gold Coast systems, moisture control is key. If neglected, your unit can become a breeding ground for nasty fungi. In this guide, DEEPCHILL will show you exactly how to spot mold early and why maintaining your air conditioning Gold Coast equipment is the best way to keep your air fresh and safe.

The “Sniff test”: Common signs of mold

You don’t need to be an expert to know when something is “off”. Usually, your nose knows first.

1. The lingering musty smell

This is the most noticeable sign. If your room smells fresh until you turn on the AC, and then suddenly smells earthy, stale, or like damp clothes, that’s mildew.

  • Split systems: If the smell is just in the lounge or bedroom, the problem is likely inside that specific unit.
  • Ducted systems: If that musty scent fills your entire home or office, you might have significant buildup in your central air conditioning Gold Coast unit or ductwork.

2. Visible patches (The fuzzy stuff)

If you look closely at your air vents or the unit itself, you might see fuzzy patches. This is the surest way to spot mold. While black or green-black spots are the most common, here on the Coast, it can also appear brown, white, powdery grey, or even pink and orange.

Close-up showing how to spot mold inside an air conditioning unit, a common issue in air conditioning Gold Coast systems affecting both residential air conditioning Gold Coast and commercial air conditioning Gold Coast.

How to spot mold in your air con safely

If the smell has tipped you off, it’s time to take a look. Here is how you can inspect your unit safely.

Safety first: Always turn off the power to your air conditioner before poking around!

For residential split systems

Most residential air conditioning Gold Coast homes have wall-mounted units. Here is the drill:

  1. Lift the face: Open the front panel.
  2. Check the filter: Pull the filters out. Look for brown, black, or greenish fuzzy stains.
  3. The flashlight test: Grab a torch and shine it behind where the filters sit. If you spot mold covering the fan blades (the roller inside), you need a deep clean.
  4. Quick tip: While inspecting, you can run a dehumidifier or place activated charcoal nearby to help absorb that damp odour temporarily.

For ducted & commercial systems

Checking commercial air conditioning Gold Coast systems or home ducted units is trickier because the main unit is hidden.

  1. Inspect the vents: Use a torch to look up into your supply vents. Look for black speckles on the louvres.
  2. Check the return air: This is the big grille in the ceiling or wall. If the filter here is clogged and fuzzy, the spores have likely spread inside.
Visual guide to spot mold on air conditioner filters and vents, highlighting indoor air quality risks in air conditioning Gold Coast for residential and commercial air conditioning Gold Coast properties.

When to call the pros?

If you manage to spot mold, wiping it with a cloth often isn’t enough. It grows deep inside the coils where you can’t reach.

Whether you need a quick service for your residential air conditioning property or a maintenance plan for commercial air conditioning premises, DEEPCHILL’s professional cleaning is the only way to kill the spores permanently.

Don’t let the growth take over.

If you have used this guide to spot mold and didn’t like what you found, contact DEEPCHILL today. We are the trusted experts for all air conditioning needs, from small homes to large commercial air conditioning projects and residential air conditioning repairs. Let’s get your air clean again!

Category: Tips & Tricks

Related Posts

Couple adjusting remote to fix autumn comfort problems at home, addressing what is the common problem with an air conditioner in fall, air conditioning Gold Coast.
Tips & Tricks
Autumn Comfort Problems Most Gold Coast Homes Don’t Notice
During this season on the Gold Coast, humidity often sitting between 60% – 80%, moisture builds up quietly inside homes....
Family relaxing under split system to use air conditioning efficiently in autumn, showing how to use air conditioning in autumn to stay comfortable and save energy in air conditioning Gold Coast homes.
Tips & Tricks
Use Air Conditioning In Autumn To Save Energy?
Autumn can be confusing. One minute it feels warm and sticky, the next it turns cool and breezy. So how...
Hand holding remote control adjusting indoor split system – temperature to set air conditioner in fall for comfortable air conditioning Gold Coast homes.
Tips & Tricks
What Temperature To Set Air Conditioner In Fall
When the heat starts to ease but the air still feels a little warm in the afternoon, many homeowners ask...
Woman turning off air conditioner with remote in living room, preparing for Turning Off Your Air Conditioner For Fall in Gold Coast climate.
Tips & Tricks
Four Things To Do Before Turning Off Air Conditioner For Fall
Fall is rolling in. Let’s find out what to do before turning off air conditioner for fall with DEEPCHILL, your...
Homeowner relaxing under a wall-mounted air conditioner during summer, highlighting what to consider before replacing an AC in heatwave conditions.
Tips & Tricks
Before Replacing Your Air Conditioner, Consider This
During extreme summer heat, many Gold Coast homeowners only realise something is wrong after their air conditioning system starts struggling....
Man using a remote to adjust wall-mounted air conditioner during summer to save power with efficient air conditioning Gold Coast setup.
Tips & Tricks
Summer AC Myths That Don’t Actually Save Power
When summer hits hard Gold Coast, most people turn to their air conditioning systems instinctively. Some habits feel energy-saving. Others...